<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>后盾人</title>
  </head>
  <body>
    <script>
      function star(row = 5) {
        let start = 0;
        do {
          let n = 0;
          do {
            document.write("*");
          } while (++n <= start);
          document.write("<br/>");
        } while (++start <= row);
      }
      star(5);
    </script>
  </body>
</html>
